Motor "Sweet Spot"

[BrianG]

I was looking over some rpm charts for various BL motors and noticed they can have quite a high amount of winds, which brings the kv down to as low as ~500. On these motors, is the sweet spot still 35k-38k rpm? If so, then they must be designed primarily for high voltage. For example, motor with a kv of 500 would need 76v to reach 38k rpm. I'd imagine the current would be quite low though.